DESCRIPTION: One goal of this research is to develop and refine models of the process whereby a speaker encodes a discrete linguistic representation of an utterance into patterns of movement of the articulatory structures and then into patterns of sound. The models will describe the ranges of variation of these patterns from a number of speakers and inferring ranges of articulatory patterns from the acoustics. Emphasis will be placed on models for consonant production in various phonetic environments. A second goal is to develop procedures for making acoustic measurements on the speech produced by speakers with certain speech disorders and for interpreting these measurements in terms of articulatory processes. Again the speech materials to be studied will consist primarily of consonants, together with measures of the laryngeal sound source. Measures will be derived for quantitative specification of the deviation of the disordered articulatory patterns from the ranges for normal speakers. The disordered populations to be studied include individuals with motor speech disorders, speakers who are severely hard of hearing, and individuals with certain laryngeal disorders. The measures of deviation from normal ranges based on noninvasive acoustic measurements are expected to have application for the diagnosis of speech disorders, for the planning of procedures for remediation of the disorders, and for quantitative evaluation of the outcome of this intervention.